> without determining, for example, that pictures of a Boston terrier and a Chihuahua both represent dogs.<p>I wonder if that is an artifact of how the training occurs. If you look at how humans generally learn, they learn what a dog is <i>first.</i> For many years they don't learn about breed (possibly ever). Cats and dogs eventually earn the shared labels "pet" and "animal".<p>However, at least in a heterosexual unit, we learn "mama" and "dada" before "woman", "man" and "person." However, we eventually learn to apply many labels to people: "name", "gender", "species" and other, possibly horrible, things.<p>In order for networks to share representation about hierarchical labels, assuming that humans are doing nothing novel in this problem space, they would either have to:<p>* Learn general labels first.<p>* Provide hierarchical labels as output.<p>* Provide multiple labels as output ("Labrador", "dog", "animal").<p>As a guess.